| 年度 | 实际值 |
|---|---|
| 1992 | 8.7 |
| 1993 | |
| 1994 | |
| 1995 | 7.4 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 8.774 |
| 2000 | 8.4977 |
| 2001 | 8.1805 |
| 2002 | 8.7729 |
| 2003 | 11.633 |
| 2004 | 12.3296 |
| 2005 | 12.7233 |
| 2006 | 12.0077 |
| 2007 | 12.0444 |
| 2008 | 12.0371 |
| 2009 | 12.5371 |
| 2010 | 15.2473 |
| 2011 | 13.7802 |
| 2012 | 13.9171 |
| 2013 | 14.0527 |
| 2014 | 16.8047 |
| 2015 | 16.9709 |